The development of a national dial plan is an involved process.
Fortunately, Cisco CallManagers deployed in North America can make use of the @
symbol to represent the various patterns that make up the North American
Numbering Plan (NANP). In this document, the @ symbol is referred to as a macro
as it represents multiple patterns. This document explains how the @ macro
works and also how to use the route filters.
The variable length patterns that the @ wildcard and the NANP covers
are as follows:
Emergency number 911
Other service numbers
Toll free numbers
Readers of this document should be knowledgeable of the
The information in this document is based on these software
The information presented in this document was created from devices in
a specific lab environment. All of the devices used in this document started
with a cleared (default) configuration. If you are working in a live network,
ensure that you understand the potential impact of any command before using
For more information on document conventions, see the
Cisco Technical Tips
Follow these instructions to configure the route pattern.
Note: Typically in the U.S., corporate users dial 9 to get an outside line
and expect a secondary dial tone.
In the Cisco CallManager Administration page, go to Route
Plan > Route Pattern. Click Add a New Route
Pattern. You will see this screen:
Note: For Cisco CallManager 4.x, go to Route Plan > Route
Pattern/Hunt Pilot > Add a New Route.
Enter 9.@ in the Route Pattern field and select
PreDot from the Discard Digits drop-down menu at the bottom of
the page in the Called Party Transformations section.
By doing this, you will not forward the leading 9 to the PSTN. The
Discard Digit instructions will vary depending upon many factors, including
gateway selection and dial peer configuration, if applicable.
Make sure you select the Gateway/Route list that will enable access
to the outside.
Check the Provide Outside Dial Tone box if you
want to hear a secondary dial tone after dialing the leading 9 and click
Note: For more information regarding the route filter, see the
Route Filter Configuration: Restricting Some Calls
From the NANP section of this document.
In the configuration in the last section, a user would have to dial the
preceding 9 before dialing 911. However, another route pattern can be added for
only 911, so that in case a user does not dial the preceding 9, the call will
still be connected. You can add this second route pattern for 911 (without the
leading 9), as shown in the screen below.
Enter 911 in the Route Pattern
Select the appropriate Gateway/Route List to reach the
Make sure that Discard Digits is set to
<None>, as we want to send all the digits to the PSTN in
An important point to remember is that the @ wildcard will give you
access to every pattern covered under the NANP. To manipulate access and
restrictions to different numbers, a basic knowledge of the NANP and route
filter is important. To understand how route filters work, let's take an
Note: Assume that the @ pattern covers the route patterns below.
01 1 3[0-469]!
If no route filter is specified in the route pattern configuration, all
the above route patterns will be part of the 9.@ route pattern. However, if you
wish to deny access to, for example, international numbers, you must use a
route filter that denies the clause International-Access and then applies this
route filter to the route pattern 9.@. In the route filter configuration, a
clause exists for every dial plan that is part of the NANP. You can explicitly
add or deny them according to your need.
Follow the steps below to configure the route filter.
Go to Router Plan > Route Filter > Add a New Route
Choose North American Numbering Plan as your dial
plan and give the route filter a name, as in the screen below.
In this route filter, chose the value "DOES-NOT-EXIST" for the
clause International-Access. Once you apply the route filter to the route
pattern, all international calls will be blocked. To better understand every
clause and its impact, use the Help > For this page link
from the top menu when you are on the route filter configuration page.
Note: If you are not in North America, or you need some other special
dial plan, study the dial plan of your country using the guidelines specified
Variable Length Dial Plans for CallManager Route Patterns - an Exercise in
Designing a Route Pattern that Covers a National Dial Plan in case you
do not want to use the ! wildcard to match all variable length patterns.
For internationalized dial plans you can download the installation
file from International Dial Plan Software Downloads
(registered customers only)
install the one you need on your Cisco CallManager to provide a unique
numbering plan specific to countries outside of North America.